lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Thu, 30 Apr 2020 22:14:11 -0600
From:   Jens Axboe <>
To:     Al Viro <>
Cc:     linux-fsdevel <>,
        "" <>
Subject: Re: [PATCH] pipe: read/write_iter() handler should check for

On 4/30/20 9:58 PM, Al Viro wrote:
> On Thu, Apr 30, 2020 at 10:24:46AM -0600, Jens Axboe wrote:
>> Pipe read/write only checks for the file O_NONBLOCK flag, but we should
>> also check for IOCB_NOWAIT for whether or not we should handle this read
>> or write in a non-blocking fashion. If we don't, then we will block on
>> data or space for iocbs that explicitly asked for non-blocking
>> operation. This messes up callers that explicitly ask for non-blocking
>> operations.
> Why does io_uring allow setting IOCB_NOWAIT without FMODE_NOWAIT, anyway?

To do per-io non-blocking operations. It's not practical or convenient
to flip the file flag, nor does it work if you have multiple of them
going. If pipes honor the flag for the read/write iter handlers, then
we can handle them a lot more efficiently instead of requiring async

Jens Axboe

Powered by blists - more mailing lists